In situ reduction of copper oxide prior to silicon carbide deposition

• US 6,878,628 B2
• Filed: 10/09/2001
• Issued: 04/12/2005
• Est. Priority Date: 05/15/2000
• Status: Expired due to Term

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Sophie, Auguste J. L., Sprey, Hessel, Soininen, Pekka J., Elers, Kai-Erik
• Primary Examiner(s): KIELIN, ERIK J
• Application Number:
  US09/975,466
• Publication Number:
  US 20020098685A1
• Time in Patent Office: 1,281 Days
• Field of Search: 438/687, 427/123, 427/124
• US Class Current: 438/687
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02301 in-situ cleaning
• CPC Class Codes: H01L 21/7681 involving one or more buried masks
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material

Abstract

The invention relates generally to improved silicon carbide deposition during dual damascene processing. In one aspect of the invention, copper oxide present on a substrate is reduced at least partially to copper prior to deposition of a silicon carbide or silicon oxycarbide layer thereon. In the preferred embodiment the reduction is accomplished by contacting the substrate with one or more organic reducing agents. The reduction process may be carried out in situ, in the same reaction chamber as subsequent processing steps. Alternatively, it may be carried out in a module of a cluster tool.

Claims

1. A process for producing an integrated circuit comprising reducing copper oxide on a substrate to leave copper from the copper oxide on the substrate while removing oxygen from the copper oxide by exposure to one or more vapor phase organic reducing agents prior to deposition of a layer comprising silicon carbide, wherein the vapor phase organic reducing agent is not plasma activated.

2. The process of claim 1, wherein the layer further comprises oxygen.

3. The process of claim 1, wherein the layer serves as a hard mask.

4. The process of claim 1, wherein the organic reducing agent comprises at least one functional group selected from the group consisting of alcohol (—

OH), aldehyde (—

CHO), and carboxylic acid (—

COOH).

5. The process of claim 4, wherein the organic reducing agent is selected from the group consisting of primary alcohols, secondary alcohols, tertiary alcohols, polyhydroxyalcohols, cyclic alcohols, and halogenated alcohols.

8. The process of claim 1, wherein said copper oxide is present after a chemical mechanical polishing (CMP) step.

9. The process of claim 1, wherein said copper oxide is formed by exposure to a clean room atmosphere.

10. The process of claim 1, wherein said exposure takes place in a first reaction chamber.

11. The process of claim 10, wherein said layer serves as an etch stop.

12. The process of claim 11, wherein deposition of the etch stop layer also takes place in the first reaction chamber.

13. The process of claim 11, wherein deposition of the etch stop layer takes place in a second reaction chamber clustered with the first reaction chamber.

14. The process of claim 11, wherein the temperature in the reaction chamber is less than about 450°

C.

15. The process of claim 11, wherein the temperature in the reaction chamber is between about 200 and 430°

C.

16. The process of claim 11, wherein the temperature in the reaction chamber is about 400°

C.

17. The process of claim 11, wherein reduction of copper oxide and deposition of the etch stop are carried out in the same reaction chamber at about the same temperature.

6. A process for producing an integrated circuit comprising reducing copper oxide on a substrate by exposure to one or more vapor phase organic reducing agents prior to deposition of a layer comprising silicon carbide, wherein the vapor phase organic reducing agent is not plasma activated, and wherein said organic reducing agent is selected from the group consisting of:

compounds having the general formula R³—

CHO, wherein R³ is hydrogen or a linear or branced C₁-C₂₀ alkyl or alkenyl group;

compounds having the general formula OHC—

R⁴—

CHO, wherein R⁴ is a linear or branched C₁-C₂₀ saturated or unsaturated hydrocarbon;

a compound of the formula OHC—

CHO;

halogenated aldehydes; and

other derivatives of aldehydes.

7. A process for producing an integrated circuit comprising reducing copper oxide on a substrate by exposure to one or more vapor phase organic reducing agents prior to deposition of a layer comprising silicon carbide, wherein the vapor phase organic reducing agent is not plasma activated, and wherein the organic reducing agent is selected from the group consisting of:

compounds of the general formula R⁵COOH, wherein R⁵ is hydrogen or a linear or branched C₁-C₂₀ alkyl or alkenyl group;

polycarboxylic acids;

halogenated carboxylic acids; and

other derivatives of carboxylic acids.

18. A process for producing an integrated circuit comprising the following steps, in order:

depositing a copper layer on a substrate;

subjecting the copper layer to a CMP process;

reducing copper oxide on the substrate to leave copper from the copper oxide on the substrate while removing oxygen from the copper oxide by contacting the substrate with one or more vapor phase organic reducing agents; and

depositing an etch stop layer on the substrate, wherein the organic reducing agents comprise at least one functional group selected from the group consisting of alcohol (—

OH), aldehyde (—

CHO), and carboxylic acid (—

COOH),

wherein the vapor phase organic reducing agent is not plasma activated.

19. The process of claim 18, wherein the etch stop layer comprises silicon carbide.

20. The process of claim 19, wherein the etch stop layer further comprises oxygen.

21. The process of claim 18, wherein the etch stop layer comprises silicon nitride.